In laser processing, it is critical to observe an image of a processing point and the peripheral area thereof in real-time in terms of explicating the processing phenomena, monitoring the processing quality and performing adaptive control of processing, therefore the potential demands for real-time observation is high.
Conventionally a laser processing head apparatus with a camera monitor, configured to irradiate a laser beam, which is deflected at a right angle by a beam splitter, onto a processing point of a processing material, and image the processing point and a peripheral area thereof using a camera, which is disposed on the rear face side of the beam splitter and on the same axis as the laser beam directed to the processing material, is known (e.g. see PTL 1).
In this apparatus, an illumination head, configured to emit light from a high brightness pulsed light source onto a processing point on a surface of a processing material, is disposed at a minimum of two locations next to the camera. From these illumination heads, processing point-emitted light including plasma generated by the laser processing, and short-pulsed laser illumination light having a brightness higher than a processing point-reflected laser beam, are actively irradiated onto the processing point, then this portion is viewed from directly above using the camera, and the processing point and the peripheral area thereof are imaged and observed.